X-rays from young stars - a summary of highlights from the XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST)

TL;DR

The XEST survey of the Taurus Molecular Cloud provides extensive X-ray spectroscopic data on young stars, revealing new features like X-ray soft excess and Two-Absorber spectra, advancing understanding of star formation.

Contribution

This paper summarizes the key findings and novel X-ray features discovered through the large-scale XEST survey of young stellar objects in Taurus.

Findings

Discovery of X-ray soft excess in classical T Tauri stars

Identification of Two-Absorber X-ray (TAX) spectra in jet-driving stars

Provision of the first coherent high-resolution spectral sample of T Tauri stars

Abstract

The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST) is a survey of the nearest large star-forming region, the Taurus Molecular Cloud (TMC), making use of all instruments on board the XMM-Newton X-ray observatory. The survey, presently still growing, has provided unprecedented spectroscopic results from nearly every observed T Tauri star, and from ~50% of the studied brown dwarfs and protostars. The survey includes the first coherent statistical sample of high-resolution spectra of T Tauri stars, and is accompanied by an U-band/ultraviolet imaging photometric survey of the TMC. XEST led to the discovery of new, systematic X-ray features not possible before with smaller samples, in particular the X-ray soft excess in classical T Tauri stars and the Two-Absorber X-ray (TAX) spectra of jet-driving T Tauri stars. This paper summarizes highlights from XEST and reviews the key role of this large project.